This invention relates in general to transport systems for transporting vehicles along guideways, an in particular to controlling steering and directional stabilization of the vehicles.
Transport systems have been proposed in the past that deal with individually transporting vehicles along guideways under automatic control. Some of the systems employ vehicles with rubber tires while others employ magnetic fields to levitate lateral supports of the vehicles at slight gaps above the tracks. Vehicles that engage the track with an air cushion have also been proposed for short, indoor transit systems. The prior art systems may include a steering and directional control system to maintain the vehicle directionally stable on the track guideway and provide steering.
Electrical brushes have been used in the past for slidingly contacting a conductor rail to transfer electrical power to the vehicle. For steering and directional control, some employ a guide roller that engages a steering rail mounted to the guideway. There are various disadvantages to the prior art systems.
In this invention, steering is provided by a pair of rail surfaces mounted along at least one of the guideways. The rail surfaces are located above a track for the lateral support of the vehicle. One of the rail surfaces faces laterally outward while the other faces laterally inward. A steering follower assembly is mounted to the vehicle for vertical movement between retracted and engaged positions. The follower assembly has a pair of follower members, each having a flat face that cooperatively engages one of the rail surfaces while in the extended position. The follower assembly is connected to a steering mechanism that steers the vehicle in accordance with lateral movement of the follower assembly as it moves along the rail surfaces.
In some of the embodiments, conductor rails are employed for both transferring electrical power and for providing directional control. Preferably at least one conductor rail is mounted to one of the guideways. The conductor rail is supplied with electrical power from a power supply. The steering follower assembly receives electrical power from the conductor rail for supplying power to the vehicle. The steering follower has a conductive brush slidingly engaging the conductor rail to supply power to the power unit of the vehicle. The steering follower also provides directional control. A steering linkage is cooperatively engaged with the conductive brush for steering the vehicle in response to lateral movement of the brush as it engages the conductor rail.
In one embodiment, a sensor is mounted to the brush for sensing lateral forces between the brush and conductor rail and providing signals to a steering actuator. The steering actuator controls the vehicle accordingly. Another embodiment utilizes an air chamber for the steering control and an electrical brush that transfers power from the rail. The air chamber has a face with a plurality of holes through which pressurized air is discharged to provide a slight gap between the rail and the air chamber.